I have heard quite a few Rotel amps over the years. Looking at possibly getting this amp to use in my system. How does this amp sound in comparison to their older class AB amps? Is it an improvement, or is there even a difference? The stereo shop was trying to say how well built these new amps are, with better amp design then previously. Or is this all fluff just to sell amps? Rotel amps I've heard before are the 970 MKii, 1070, 850 and a couple others.